Thanks for all the votes so far. Looks like a close race between S-PVA and S-IPS. We'll have to see if it separates at all as more votes come in. Any specific reason why no one has voted for the IPS Alpha?

In contrast, CNET describes the black level of the Panasonic LZ85 with the IPS alpha panel as, "In dark areas, the Panasonic delivered a relatively deep shade of black--just a tad darker than the other small-screen displays" (http://reviews.cnet.com/flat-panel-t...?tag=mncol;lst) (though CNET did criticize the set for its poor grayscale tracking and lack of RGB controls, but that's a model issue and not because of the panel).

I think the only other manufacturer that uses IPS alpha panels aside from Panasonic is Hitachi... so you're kind of limited in choices.

The other issue is that, at least in computing, most IPS displays from the past couple of years use H-IPS, not S-IPS. I don't know whether LG.Philips-sourced IPS TVs are now using H-IPS as well, and I'm also uncertain how H-IPS compares to IPS Alpha (there don't appear to be any computer monitors using Alpha).

Wikipedia has a chart of Hitachi (Alpha) v LG IPS technologies and their evolution.

PVA is inferior to IPS overall, especially for computing purposes, but viewed at a couple of metres, PVA's weaknesses are less apparent, and its strengths (blacks, contrast) are critical in a home theatre setting.

Another shortcoming of IPS: I don't think there are any large IPS panels (and I'm hesitant to believe even the LG47s are IPS).

I personally would select H-IPS for a computer monitor (my dream display is the 24-inch NEC), but for a large TV I suspect I might have to choose PVA (since we're not permitted to choose plasma ).

The other issue is that, at least in computing, most IPS displays from the past couple of years use H-IPS, not S-IPS. I don't know whether LG.Philips-sourced IPS TVs are now using H-IPS as well, and I'm also uncertain how H-IPS compares to IPS Alpha (there don't appear to be any computer monitors using Alpha).

Wikipedia has a chart of Hitachi (Alpha) v LG IPS technologies and their evolution.

PVA is inferior to IPS overall, especially for computing purposes, but viewed at a couple of metres, PVA's weaknesses are less apparent, and its strengths (blacks, contrast) are critical in a home theatre setting.

Another shortcoming of IPS: I don't think there are any large IPS panels (and I'm hesitant to believe even the LG47s are IPS).

I personally would select H-IPS for a computer monitor (my dream display is the 24-inch NEC), but for a large TV I suspect I might have to choose PVA (since we're not permitted to choose plasma ).

"All of LG's LCD HDTVs use Super In Plane Switching (S-IPS) LCD panel structure." However, I read somewhere else that it's only on their 32" and above models. Your guess is a good as mine, but sticking with 32" and above LG's this year will DEFINITELY get you an S-IPS panel. http://www.hdtvlounge.net/lg/2009-lineup/

So it sounds like it comes down to whether I want reduced pixel and input lag or better black levels.

Since I'll mostly be watching sports and action movies, with about 1/5 of the time being video games, it seems as though the reduced pixel and input lag would be important? Especially when considering that most of my TV time is spent on ESPN, which has the scrolling bar on the bottom of the screen. Am I correct in assuming that reduced pixel lag will result in less blurring on an S-IPS panel when compared to a PVA? On the TV's I'm looking at, the S-IPS has a response time of 6ms, and the PVA has a response time of 8ms. Sounds like the S-IPS will blur significantly less?

poor input lag due to overdriving the display to make pixel lag up to par with S-IPS

S-IPS
black levels and therefore contrast worse than S-PVA

good colors even just as good as S-PVA

good viewing angle

best pixel lag and input lag, only surpassed by TN panel that have very poor colors and viewing angles

Therefore

if your a gamer and hate lag. get an S-IPS

if your not a gamer or do not care much about input lag get a S-PVA panel because they will have a better picture mainly due to better black levels and contrast

As far as black levels and contrast go, for the TV's I'm looking at, the S-IPS has a much higher contrast ratio (30,000:1) than the S-PVA (13,000). I know different companies rate them differently, but this seems like a big enough difference that it actually does have a higher contrast (I'm guessing because of the engine). Due to this, would the black levels probably be more comparable between the two? The models are the LG 32LH20 (S-IPS) and the Sony Bravia KDL-32L5000. In the store they looked comparable, but you can't tell anything based on the store settings, and the TV's are too new to get any good reviews already.

As already been said it depends on your needs...
If you want a TV for mostly daytime viewing or you are going to watch it from different parts of a room than IPS is probably better for you.
If your TV viewing mostly at night and your sitting position is in front of the TV you probably would be better with S-PVA.

1. Blacks
S-PVA definitely better in this regard.

2. Color accuracy
Both technologies are very good and comparable.
Personally I think latest IPS panels from LG and especially Alpha have a slight edge over S-PVAs (in a comparable price category).

3. Resistance to color shift when viewed at different angles
IPS panels are better in color shift tests. Go to any Samsung or Sony LCD forum and you'll see complains how bad viewing angles are.
However, IPS panels suffer from some light bleeding when viewing at angles. That's the drawback of IPS.

4. Resistance to motion blur
IPS is slightly better, but latest S-PVAs almost comparable to IPS in this regard.

One other note.
S-PVA technology prone to dreadful flashlighting and clouding effects.
About half of S-PVA based TVs suffer from this (at least according to polls here on forums). It is a inheritable illness of this tech.
And as I noted above IPS panels have viewing angles light bleeding .
Nothing perfect in this world. You chose the imperfection.

As already been said it depends on your needs...
If you want a TV for mostly daytime viewing or you are going to watch it from different parts of a room than IPS is probably better for you.
If your TV viewing mostly at night and your sitting position is in front of the TV you probably would be better with S-PVA.

1. Blacks
S-PVA definitely better in this regard.

2. Color accuracy
Both technologies are very good and comparable.
Personally I think latest IPS panels from LG and especially Alpha have a slight edge over S-PVAs (in a comparable price category).

3. Resistance to color shift when viewed at different angles
IPS panels are better in color shift tests. Go to any Samsung or Sony LCD forum and you'll see complains how bad viewing angles are.
However, IPS panels suffer from some light bleeding when viewing at angles. That's the drawback of IPS.

4. Resistance to motion blur
IPS is slightly better, but latest S-PVAs almost comparable to IPS in this regard.

One other note.
S-PVA technology prone to dreadful flashlighting and clouding effects.
About half of S-PVA based TVs suffer from this (at least according to polls here on forums). It is a inheritable illness of this tech.
And as I noted above IPS panels have viewing angles light bleeding .
Nothing perfect in this world. You chose the imperfection.